>Eerily good for bands I know of. How do they collect data?
If you type an artist that they don't know much about, you'll write the bands you like most, and from that you'll answer a few questions about bands similar to the bands you wrote.
I guess that's where the small errors come in (I noticed some polar oposite bands; Progressive Rock and Rap don't tend to mix). People who enjoy multi-genres of music kind of scramble the data I suppose.
Ghan has said he has fixed this. Monovertex please confirm this fix. This was only a problem with people that had signatures in the upper levels like not the special members but the respected members.